Part for a sofa bed



FIG. 1 is a perspective view of a part for a sofa bed, showing my new design;

FIG. 2 is a top view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a side view thereof;

FIG. 5 is an opposite side view thereof;

FIG. 6 is an end view thereof; and,

FIG. 7 is an opposite end view thereof. 

CLAIM I claim, the ornamental design for a part for a sofa bed, as shown and described. 